But it doesn't adjust your local time until you log in.
Oops sorry - I rushed my answer as I was heading off to a meeting and was way too obtuse.
1) when you access the site it obtains the IP address of where your browser is connected to the internet. Even if you are not logged in.
Some software systems use this IP address as your physical location. SB does not. Your IP address may be somewhat related to your real location but it may not be. You can fool the system by connecting via a VPN service that may allow you to connect from almost anywhere in the world without you physically moving from your lazyboy.
When I travel I use a VPN service to pretend I am still at home(ish) when accessing my bank accounts (this is too fool the bank's stupid security system).
2) SB has no idea who is pressing the keys. Once you log in it assumes it is you (it could be anyone) and provides a more personal experience by doing nice things for you. Things like:
- displaying times in whichever timezone you have selected in your profile preferences. You are free to choose any timezone. It does not have to be associated with your perceived location based on IP address.
- tracking read threads, new posts, etc....
- access to special forums
If you are not logged in then SB will display times in the "guest timezone". There is only 1 guest timezone. All non logged in users see the same guest timezone regardless of their location.